1. Field of the Invention
The present invention relates to an apparatus for reading information stored on a magnetic strip card and transmitting the data to a remote location. More particularly, the present invention relates to the fabrication of a high resolution, low profile credit card reader, especially for use with a credit card, phone card, or the like.
2. Description of the Related Art
Plastic cards having electronically stored data are widely used to perform a large variety of tasks, from being used as conventional credit, telephone, or bank cards to use as a security key to operate a door lock. Other types of cards are gasoline credit cards, building, room and/or elevator security access cards, personnel cards, Automated Teller Machine (ATM) cards, debit cards and cash cards. For purposes of this application, however, these cards will be generically referenced as xe2x80x9cauthorization cardsxe2x80x9d or just xe2x80x9ccards.xe2x80x9d
Authorization cards fall into three general categories: magnetic, electronic or xe2x80x9csmart cards,xe2x80x9d and passive electronic cards. Confidential information, such as a unique account or card number, is typically stored on the card. In addition, the card number is printed on the face of the card, usually together with other security information such as the owner""s name, the card""s expiration date, and/or a Personal Identification Number (PIN).
In order to complete a given transaction at the point of sale, the card number and/or other confidential information is transmitted from the card to a card reader for recognition and authorization by running the card through the card reader.
Problems arise with the use of conventional inductive read head credit card readers, particularly when they are attached or connected to such devices as personnel computers, laptops, hand held computing devices and cell phones. The prior art inductive read head is not well suited to such small portable electronic devices. The strength of the signal from an inductive head depends on the rate of travel of the magnetic stripe past the gap in the magnetic core of the head. The faster the travel, the larger the voltage induced in the pickup coil of the head. The card must be guided during its motion so that the magnetic stripe is moving in close proximity to (usually in contact with) the pole tips of the head core. The required motion and control is usually obtained by holding or affixing the card reader firmly to a surface and swiping the card through the guide slot. The guide slot is generally longer than the credit card (80 mm) and about 10 mm deep. The size and shape of the device make it difficult to integrate with small portable electronic devices. Also the motion required is sometimes incompatible with the operation of the device. For example, it would be difficult to swipe a credit card through an inductive card reader attached to the side of a cell phone while carrying out voice communication with the merchant.
Fabrication of credit card readers, which typically relies upon photolithography, is also a rather exacting process involving a series of steps. A simpler method of fabrication that does not require lithography would be desirable.
It is therefore a primary object of the present invention to provide a method for fabricating a low profile credit card reader suitable for use with small devices.
It is a further object of the invention to provide a method for fabricating a high resolution magnetoresistive sensor for reading magnetically stored digital information on a credit card without lithography.
It is a further object of the invention to provide a card reader having an output that is independent of the speed of motion of the card with respect to the sensor.
It is a further object to provide a card reader that is less subject to mechanical wear.
It is yet another object of the invention to provide a card reader capable of large voltage signals.
It is another object of the invention to provide a card reader that can operate in conjunction with existing magnetic cards.
It is still another object of the invention to provide a thin profile card reader suitable for small portable electronic devices through the use of magnetoresistive sensing elements.
It is another object of the invention to provide means for reading data stored on an authorization card and sending the data over a telephone to a remote card reader receiver.
It is a further object of the invention to provide a card that generates a sound that is converted to an electronic signal that can be transmitted over a telephone line, and to provide a card reader that is portable and lightweight and can be carried in a pocket, wallet or purse.
In accordance with the above objects, the present invention is a portable card reader that is designed to be carried in a wallet or purse. In a first embodiment, the card reader has an electromagnetic head that reads information from a magnetic strip of a card. In a second embodiment, information is read from the card by an array of Hall sensors. In a further embodiment, the card reader uses a magnetic sensor based on magnetoresistive sensing of magnetic transitions of a magnetic stripe. In each embodiment, the information read from the card may be converted to a sequence of sound bursts of predetermined frequency, preferably in the audible or ultrasound range. The sound signals are output by a speaker to the microphone of a telephone. The signal is then transmitted over the telephone lines to a remote receiver which converts the sound bursts into signal pulses which can be read using the computer software of a conventional card reader.
The present invention is also directed to a method for fabricating a credit card reader that offers both high resolution and low profile. The card reader uses a magnetic sensor based on magnetoresistive sensing of the magnetic transitions of a magnetic stripe.